scholarly journals Improvement of Ips typographus catches in pheromone trap barriers by altering of sex assigned pheromone blends

2021 ◽  
Vol 48 (1) ◽  
pp. 25-34
Author(s):  
Miroslav Blaženec ◽  
Andrej Majdák ◽  
Rastislav Jakuš

Abstract The present study was based on the idea of a pheromone trap barrier with alternating dispensers releasing different pheromone mixtures that affect males and females differently. We tested the possibility of increasing the catch efficacy of pheromone trap barriers by altering the pheromone mixture with low levels of cis-Verbenol (cV, targeting males, BM), the mixture with high levels of cV (targeting females, BF) and the pheromone mixture with intermediate levels of cV (SL). In addition, we were interested in lowering the dispersion of attracted bark beetles, especially males, which reduces the risk of attack on trees in the surroundings. Significant highest absolute and relative catch was found in the catch of the combination BM–BF, which was 2.2-fold higher than the catch of the control barrier treated with commercial IT Ecolure baits (Fytofarm, Slovakia). At the same time, the lowest dispersal in the surroundings of the barrier with the combination BM–BF was found, which was 2.5-fold lower than in the control barrier. The performance of the BM–BF combination of mixtures was proved in a field trial experiment where the total season catch of the part of the barrier treated with BM–BF dispensers caught 1.5-fold more beetles during the season than the control part treated with IT Ecolure dispensers. Furthermore, the results confirm that the performance of the combination of low levels of cV (targeting males) and high levels of cV (targeting females) is complemented by the desired reduced dispersion around the barrier, which reduces the risk of attack on trees in the surroundings.

2014 ◽  
Vol 60 (No. 10) ◽  
pp. 401-405
Author(s):  
M. Zahradníková

There are only two known methods for determining the sex of Ips typographus (L.) – dissection that can­not be used with live beetles and by distinguishing between the density of the hairs on the head, a less reliable method that requires experienced personnel. As a result, we have sought to find a more reliable method of sex determination for I. typographus which can be used with live specimens but is still reliable and easy to conduct. The aim of the article is to explore the inner structure in data from measurements of morphological parameters of spruce bark beetles and to find correlations which could be used for sex determination. The number of beetles in our sample was 110, all from the first trapping of one pheromone trap. The statistical methods of principal components analysis (PCA) and cluster analysis (CLU) were used to support any correlation between the sex parameter and other morphological parameters (weight, elytra length, elytra width, pronotum length, pronotum width). As no correlation was found in the case of sex, we can claim that it is not possible to determine sex according to the examined morphological parameters. However, we have found an interesting inner structure in the data and it was confirmed that even weight is slightly correlated with other morphological parameters.  


Chemoecology ◽  
2021 ◽  
Author(s):  
Lina Viklund ◽  
Joakim Bång ◽  
Martin Schroeder ◽  
Erik Hedenström

AbstractBark beetles of the genus Polygraphus have recently been involved in large bark beetle outbreaks in central Sweden, together with the European spruce bark beetle Ips typographus. Three species of Polygraphus can be found in this region; Polygraphus poligraphus, Polygraphus punctifrons and Polygraphus subopacus. Efficient pheromone traps would facilitate further investigations of these species and their role in bark beetle outbreaks. Pheromone compounds have previously been identified in P. poligraphus and P. punctifrons, but not in P. subopacus. Thus, we allowed males and females of P. subopacus to bore in the bark of stem sections of Norway spruce (Picea abies) in the laboratory. Volatile organic compounds from boring insects were sampled with SPME and analysed with GC–MS and several male-specific compounds were observed. The male specific compounds were 3-methyl-3-buten-1-ol, 3-methyl-2-buten-1-ol, 3-methyl-2-butenal, grandisol, fragranol, (Z)-2-(3,3-dimethylcyclohexylidene)-ethanol, (E)-2-(3,3-dimethylcyclohexylidene)-ethanol, (Z)-2-(3,3-dimethylcyclohexylidene)-acetaldehyde, (E)-2-(3,3-dimethylcyclohexylidene)-acetaldehyde, geranial and γ-isogeraniol. (Z)-2-(3,3-dimethylcyclohexylidene)-ethanol, [(Z)-DMCHE], was identified from GC–MS analysis to be the major male-specific compound while the (E)-isomer, [(E)-DMCHE], was found as a minor compound. These two compounds gave positive responses in EAG analyses with antennae from males and females of P. subopacus. Thus, (Z)- and (E)-DMCHE were used in a field experiment in central Sweden but only (Z)-DMCHE was found to be attractive to males and females of P. subopacus. Consequently, (Z)-DMCHE was established to be a component of P. subopacus aggregation pheromone.


2021 ◽  
Vol 6 (6) ◽  
pp. 98-105
Author(s):  
A.A. Chalkin ◽  
◽  
S.N. Lyabzina ◽  
E.V. Sinitsyna ◽  
A.Yu. Lobur ◽  
...  

Hereafter, the results on the comparative analysis of Pityogenes chalcographus and Ips typographus monitoring by the use of pheromone traps are represented. The field trial was conducted within four different forest cenosis of the national reserve area «Kivach». The barrier funnel shaped traps with a lure attracting the bark beetle Pityogenes chalcographus and Ips typographus produced by FGBU «VNIIKR» were used for the pest monitoring in the four different cenosis. The results suggest that there is a positive correlation between the caught pest number and the type of a cenosis where the pheromone traps were installed.


Biologia ◽  
2014 ◽  
Vol 69 (1) ◽  
Author(s):  
Rudolf Wegensteiner ◽  
Andrea Stradner ◽  
Uwe Händel

AbstractThe study presents new data on spatial distribution of bark beetle pathogens, on changes in frequency over several years and on their prevalence during different time periods within a year from several locations within the wilderness reserve Dürrenstein (Lower Austria). The occurrence of pathogens was investigated in Ips typographus (during five years), in Pityogenes chalcographus (during two years) and in Ips amitinus (in one year). In total, seven pathogen species could be detected in I. typographus. The most dominant pathogen species were the Ips typographus-Entomopoxvirus (ItEPV), the sporozoan species Gregarina typographi and the microsporidium Chytridiopsis typographi; the latter two pathogen species were recorded every year and at about similar high (G. typographi) or low (C. typographi) rates, the ItEPV in strongly varying rates. The neogregarine Mattesia cf. schwenkei and the two microsporidia Nosema typographi and Unikaryon montanum were found in I. typographus only sporadically and the rhizopodan species Malamoeba scolyti was found once. The number of infected males and females was relatively similar with almost all pathogen species in most of the years except U. montanum, which occurred exclusively in females. Three pathogen species were recorded in P. chalcographus which were Gregarina typographi, Mattesia cf. schwenkei and Chytridiopsis typographi. Two pathogen species were observed in I. amitinus, Gregarina typographi and Chytridiopsis typographi.


Forests ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1290
Author(s):  
Branislav Hroššo ◽  
Pavel Mezei ◽  
Mária Potterf ◽  
Andrej Majdák ◽  
Miroslav Blaženec ◽  
...  

Research Highlights: Bark beetles are important agents of disturbance regimes in temperate forests, and specifically in a connected wind-bark beetle disturbance system. Large-scale windthrows trigger population growth of the European spruce bark beetle (Ips typographus L.) from endemic to epidemic levels, thereby allowing the killing of Norway spruce trees over several consecutive years. Background and Objectives: There is a lack of evidence to differentiate how outbreaks are promoted by the effects of environmental variables versus beetle preferences of trees from endemic to outbreak. However, little is known about how individual downed-tree characteristics and local conditions such as tree orientation and solar radiation affect beetle colonization of downed trees. Materials and Methods: To answer this question, we investigated the infestation rates and determined tree death categories (uprooted, broken, and stump) in wind-damaged areas in Western Tatra Mts. in Carpathians (Slovakia) from 2014–2016, following a windthrow in May 2014. In total, we investigated 225 trees over eight transects. For every tree, we measured its morphological (tree height, crown characteristics), environmental (solar radiation, terrain conditions, trunk zenith), temporal (time since wind damage), and beetle infestation (presence, location of attack, bark desiccation) parameters. We applied Generalized Additive Mixed Models (GAMM) to unravel the main drivers of I. typographus infestations. Results: Over the first year, beetles preferred to attack broken trees and sun-exposed trunk sides over uprooted trees; the infestation on shaded sides started in the second year along with the infestation of uprooted trees with lower desiccation rates. We found that time since wind damage, stem length, and incident solar radiation increased the probability of beetle infestation, although both solar radiation and trunk zenith exhibited nonlinear variability. Our novel variable trunk zenith appeared to be an important predictor of bark beetle infestation probability. We conclude that trunk zenith as a simple measure defining the position of downed trees over the terrain can anticipate beetle infestation. Conclusions: Our findings contribute to understanding of the bark beetle’s preferences to colonize windthrown trees in the initial years after the primary wind damage. Further, our findings can help to identify trees that are most susceptible to beetle infestation and to prioritize management actions to control beetle population while maintaining biodiversity.


Author(s):  
Peter H. W. Biedermann ◽  
Jean-Claude Grégoire ◽  
Axel Gruppe ◽  
Jonas Hagge ◽  
Almuth Hammerbacher ◽  
...  

Tree-killing bark beetles are the most economically important insects in conifer forests worldwide. Yet  despite >200 years of research, the drivers of population eruptions or crashes are still not fully understood, precluding reliable predictions of the effects of global change on beetle population dynamics and impacts on ecosystems and humans.  We critically analyze potential biotic and abiotic drivers of population dynamics of the European spruce bark beetle (Ips typographus) and present a novel ecological framework that integrates the multiple drivers governing this bark beetle system. We call for large-scale collaborative research efforts to improve our understanding of the population dynamics of this important pest; an approach that might serve as a blueprint for other eruptive forest insects.


2016 ◽  
pp. 59-68
Author(s):  
Mara Tabaković-Tošić ◽  
Marija Milosavljević

The paper presents the results of the research on the correlation between changes in microclimate, the intensity of spruce decline and active abundance of its two economically most significant harmful insects-eight-toothed (Ips typographus) and six-toothed (Pityogenes chalcographus) spruce bark beetles (Coleoptera: Curculionidae) in Golija Nature Park whose pure and mixed conifer stands are dominated by spruce. The route method and ocular inspection were applied to study the presence and determine the intensity of spruce decline-both of individual trees and groups of trees in the management units of Dajićke planine, Kolješnica, Golija and Brusničke šume. Population dynamics of the two species of bark beetles and their active abundance were monitored by the method of trapping with barrier traps and the use of combined pheromone dispensers-PCIT Ecolure. Although the decline of individual conifer trees, primarily of spruce, had already been present in certain areas of these management units for several decades, it reached epidemic proportions due to extreme adverse climatic conditions in the period between 2011 and 2012 and culminated in 2015. A large number of physiologically weakened trees raised the population levels of secondary harmful insects and the number or the active abundance of the two investigated species of insects reached a peak in 2016. The inability to take appropriate and timely remedial measures in the areas under stricter protection regimes greatly contributed to this situation.


1991 ◽  
Vol 81 (1) ◽  
pp. 11-20 ◽  
Author(s):  
E. Busch-Petersen ◽  
H. Baumgartner

AbstractGenetic systems have been developed in several insect species for separating males and females prior to releasing sterilized males in pest control programmes using the sterile insect technique. The systems generally depend on translocating a readily selectable gene onto the Y chromosome. A potential source of instability in such a system is genetic recombination in the male. Although such recombination was originally thought to be absent in most cyclorrhaphous Diptera, low levels have recently been found. We have developed a computer model which simulates the progression of instability in the presence of male recombination, which can be used to assess the influence of rate of recombination in combination with a range of associated genetic and biological parameters. Male recombination alone or fitness of the Y-linked translocation were found to contribute relatively little to the rate of progression of instability. By contrast reduced fitness or mating competitiveness associated with the selectable gene had a strong effect. The sex ratio and the ratio of carriers to non-carriers of the selectable gene showed patterns characteristic of the parameters modelled. The relevance of such data to the development of suitable strains for genetic sex-separation and the replacement of strains under mass rearing conditions are discussed.


2019 ◽  
Vol 49 (8) ◽  
pp. 903-914 ◽  
Author(s):  
Frida A. Zink ◽  
Luke R. Tembrock ◽  
Alicia E. Timm ◽  
Todd M. Gilligan

Bark beetles in the family Curculionidae present a growing hazard to forests worldwide. Like native bark beetles, introduced exotic species can pose a serious threat to North American forests. Ips typographus (Boerner) and Ips sexdentatus (Linnaeus), both native to Europe, are two such pests that have caused widespread forest loss in their native ranges. International trade has led to increased interceptions of Scolytine beetles at ports of entry to the United States. Most intercepted individuals are not identified to species due to lack of expert identifiers, poor specimen quality, or incomplete taxonomy. These same problems affect identification for domestic surveys. Therefore, development of molecular methods for identification of potentially invasive Ips species is essential. Because of the need to scrutinize large numbers of beetles in an efficient manner, we describe a duplex droplet digital PCR (ddPCR) assay to identify I. typographus and I. sexdentatus simultaneously in bulk trap samples containing 500 Scolytinae specimens using a scalable, two-step DNA extraction. This ddPCR method is highly effective for processing the entire contents of beetle traps and identifying these potentially invasive species in a timely and definitive manner. We also describe a nondestructive DNA extraction technique that preserves specimens for morphological identification.


2014 ◽  
Vol 82 (3) ◽  
pp. 518-532 ◽  
Author(s):  
Daniel C. Fisher ◽  
Michael D. Cherney ◽  
Cody Newton ◽  
Adam N. Rountrey ◽  
Zachary T. Calamari ◽  
...  

AbstractAt an altitude of 2705 m in the Colorado Rockies (USA), the Ziegler Reservoir fossil site gives a rare look at a high-elevation ecosystem from the late Pleistocene (especially MIS 5) of North America. Remains of more than four mammoths and about 35 mastodons dominate the macrofossil assemblage. Mammoth remains are attributed to Mammuthus columbi, and mastodon remains are referred to the well-known, continent-wide Mammut americanum. Mastodon remains occur within and between several lake-margin slump deposits. Their deposition must therefore have occurred as events that were to some degree separate in time. We treat the mastodon assemblage in each stratigraphic unit as a source of information on environmental conditions during the lives of these individuals. Mastodon mandibular tusks are abundant at the site and represent both males and females, from calves to full-grown adults. This study presents the first attempt to use microCT, thin-section, and isotope records from mandibular tusks to reconstruct features of life-history. We recognize an up-section trend in δ18O profiles toward higher values, suggestive of warmer temperatures. Throughout this sequence, mastodon growth histories show low mean sensitivities suggestive of low levels of environmental stress. This work helps frame expectations for assessing environmental pressures on terminal Pleistocene populations.


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